Action for pneumatic musical instruments.



No. 675,468. Patented lun 4, I901.

c. L. DAVIS. ACTION FOB PNEUMATIC MUSICAL INSTRUMENTS.

(Application filed Aug. 15, 1900.)

(In Iodol.)

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UNITED STATES PATENT OFFICE.

CHARLES L. DAVIS, OF CHICAGO, ILLINOIS, ASSIGNOR OF ONE-HALF TO AUGUST HEUER, JR., OF SAME PLACE.

ACTION FOR PNEUMATIC MUSICAL INSTRUMENTS;

SPECIFICATION forming part of Letters Patent No. 675,468, dated June 4, 1901.

A li ti fil d August 15, 1900. Serial No. 26,992. (No model.)

To all whom it may concern:

Be it known that I, CHARLES L. DAVIS, a citizen of the United States, residing at Chicago, in the county of Cook and State of Illinois, have invented a certain new and useful Improvement in Actions for Pneumatic Musical Instruments, (Case No. 4,) of which the followingis afull, clear, concise, and exact description, reference being had to the accompanying drawings, forming a part of this specification.

My invention relates to actions by which a positive stroke can be secured in pneumatic musical instruments-such, for example, as mechanical piano-players. Although the invention is capable of use in substantially any pneumatic musical instrument, I have shown it embodied in an arrangement for operation in a mechanical piano-player, and hence will describe it in connection with that instrument, although I do not desireto'be limited in its application thereto.

In mechanical musical instruments such as are adapted to operate a piano or other instrument having a keyboard it is well known that the mechanical musical instrument is provided with a series of operating-fingers which are arranged in connection with and above the keys of the piano or like instrument when the mechanical musical instrument is placed in position in front of a piano, so as to operate the same. These key-actuating fingers of the musical instrument are connected with aseries of pneumatic-actions, or pneumatics, as they are commonly called, each one of which is arranged for operating one of the keys.- Thepneumatic-actions are generally actuated so as to actuate their respective fingers by the variation in the pneumatic pressure in their interiors.

one with one of a series of ports in what is known as a tracker-board, so that the admission of air into those ports will cause the actuation of the corresponding pneumatics. The admission of air into'the tracker-board ports is controlled by a traveling sheet of music having perforations adapted to register with the ports'of the board. These perforations are so situated that they come into register with the tracker-board ports at proper instrument.

A commonway of bringing this about is to connect each times to cause the actuation of the pneumatics controlling the keys which are to play the musical composition. In this way the proper keys are played at the proper time by the fingers of themechanical musical instrument, so as to play various musical compositions.

The invention of the present application relates in particular to the pneumatics or pneumatic-actions by which the key-actuating fingers of the mechanical piano-player are controlled. 3

The principal objects of the invention are to secure a quick, rapid, decisive, and eifeotive stroke of the key-actuating fingers. and to procure this result by simple, inexpensive, and practical means.

In the accompanying drawings, Figure 1 is a' view, partly in elevation and partly in sectio n, of a pneumatic or pneumatic-action embodying my invention. Fig. 2 is an elevation of the same, showing its connection andar-t, rangement in a mechanical piano-player for operating one of the fingers of a piano or like In the arrangement illustrated in the drawings I provide a series of pneumatics or bellows A A for actuating the fingers of the pianoplayer, one. pneumatic being arranged for each finger. These pneumatics are conveniently provided with links 13 B, andthe ends of the links B B are connected with bellcranks C C, whose opposite arms are arranged and adapted to strike the piano-keys D D. The pneumatics or bellows A A are understood to be sufficiently strong to give an effective and decisive stroke to the piano-keys throughthe agency of the mechanism illus vided with a passage 1, shown as leading downwardly therefrom and having at its opposite end ports 2 and 3. The ports 2 communicate with the outside atmosphere and the ports 3 3 communicate with a vacuumchamber E, which is understood to be contrated. Each ofthe pneumatics A'A.iS.p1'0-' nected with a pressure-reducing apparatus.

The ports 2 and 3 of each pneumatic are controlled by valves 4 and 5, both ofwhich are shown arranged upon the same valve-spindle 6. When the valve-spindle 6 is in a lowered position, as shown in the left-hand pneumatic in Fig. 1, the port 2 is opened and the port 3 closed, thereby closing. the pneumatic to the normal. air-pressure and opening it to the vacuum-chamber or to an air-pressure lower than the normal atmospheric pressure. The ends of the valve-spindle 6 6 are attached to diaphragms 7 7, and these diaphragms 7 7 are arranged over the ends of the passages ,8 8,

leading from various tracker-board ports. It.

port 2. and open the vacuum-port 3. This will open theinterior of the pneumatic A to theexhaust-chamber E, and thereby permit the air in the pneumatic to be withdrawn.

As aresult the outside atmosphere will act upon the exterior of the pneumatic and col lapse the same, so as-to cause aquick and decisive stroke of the connected key-actuating finger. When the air-pressure isshut off fromthe tracker-board port by the traveling sheet of music,,th e airremaining therein is withdrawn therefrom and from the passage 8 by a. small bleeder-port 10, arranged along- .side of the diaphragm 7. A- condition of exhaust is thusestablished in. the tracker-port passage and. the diaphragm 7 collapses,-thereby allowingthe valve-spindle 6 to descend of its own weight and open the air-port 2'and close the exhaust-port 3. This allowsthe entrance-of the outside air into the pneumatic A, and thusestablishes therein a condition of equilibrium with the exterior atmosphere.

I As-an arrangement for returningthe pneumaticA to its normal position I have shown I matic combined with meanswhereby it can- ;be actuated by pneumatic pressure, and a i supplemental pneumatic.tendingnormally to restore the first-mentioned pneumatic to its 3 original condition, the second pneumatic bein g relatively weaker thanthe.fi'rst-mention'ed.

asupplemental pneumatic F, arranged in connectionwith each pneumatic A, This pneumatic F'is provided with a port 11,'extending' from its interior to the vacuum-chamber E and normally maintained in an open condition,.so that there is always an exhausted con.- dition withinthe pneumatic F. This supplemental pneumatic F is arranged so that it always tends to restore the pneumatic A to its 2 original condition, a simple arrangement beingrto connect the collapsible material of the, pneumatic F to the swinging leaf or flap a ofthe pneumatic A, in which way the pneumatic F in. tending always to collapse exerts continually a pressure or force tendingfto swing the flap a back to itsnormal position. The

pneumatic F, ho'wever,is considerably weaker than the pneumatic A, as by making it con-.

siderably smaller relativelywthereto, so that 3 the pneumatic A can act in opposition to the supplemental pneumatic F when the formeris exhausted as a result of the admission of air into its tracker-board port. By this arrangement it will be seen that when air is admittedto one of the tracker-board ports and a condition of exhaust is established in the pneumatic A as a result thereof this pneumatic will act quickly and powerfully in op position to the pnenmaticF, but that when the air is shut off from that tracker-board port and a condition of equilibrium is established in the pneumatic A as a result thereof the supplemental pneumatic F will immediately act to restore the pneumatic A to its original condition. These acting and return strokes are made rapidly, quickly, and effectively. It will be also seen that when the primary pneumatic operates the supplemental pneumatic has less power relatively, be-

cause of the condition of equilibrium established between it and the main pneumatic. It will be further seen that the arrangement illustrated is simple, inexpensive, andzpractical and that it involves a minimum number of parts-that is to say, a single large 5 pneumatic and a single valve mechanism.

Although I have thusdescribed a specific structure shown in the drawings, I donotdesire it to be considered that I Wish. to limit myself either to-that' specific structure: or

to the specific embodiment of the invention which it entails. specific structure can bevaried and also that 3 the principleof the invention as contained therein can becarried out by structu-res-varying very materially in, arrangement and-operation.

I am fully aware that the What I claimas my. invention ismental'pneumatics,-of means for maintainin g the atmospheric pressure normally in the main pneumatic, means for exhausting the air from such pneumatic as'desired,, and meansfor maintaining a vacuum constantly in the supplemental pneumatic, substantially l as set forth. I t

2. A pneumatic-action comprising apneu- 5 sition to the former.

3. In apneumatic-action, the combination witha pneumatic, of valve mechanism for controlling theadmission andexhaust of air therefrom, anda supplemental pneumatic tending normally to restore the first-mentioned pneumatic to itsoriginal condition, the supplemental pneumatic being'relatively smaller than the first-mentioned pneumatic,

1 whereby the latter can operate inpopposition to it.

4:. In a pneumatic-action, the combination of a pneumatic having a passage leadingthere= from, the said passage being provided with 675,468 y p I matic relatively weaker than the first-men- .tioned one, the said supplemental pneumatic u having a passage normally andcontinuously establishing communication between its interior and the'said exhaust-chamber.

5. In a pneumatic-action, the combination with a pneumatic, of means for maintaining a condition of equilibrium therein, means for varying said condition so as to cause the pneumatic to act, a supplemental pneumatic relatively weaker than themain pneumatic, and means for maintaining in the supplemental pneumatic a pneumatic condition tending to cause it to actuate the main pneumatic.

6. In a pneumatic-action, the combination of a main and a supplemental pneumatic, the latter being relativelysmallerthan theformer and having its collapsible material attached I to the movable member of the main pneumatic, an exhaust-chamber, passages leading from said pneumatics, the passage from the main pneumatic having'a port terminating at said exhaust-chamber and another port communicating with the outside atmosphere and the passage leading from the supplemem tal pneumatic terminating at said exhaustchamber, a valve-spindle carrying valves respectively controlling the ports of said 'primary-pneumatic passage, a diaphragm attached to said valve-spindle and arranged in the exhaust-chamber, a tracker-board port terminating at said diaphragm, and a bleederport establishing communication between the exhaust-chamber and the tracker-board pas- 5 sage.

7. The combination with main and supplemental pneumatics and with a vacuum-chamber, of a passage extending from the main pneumatic and having an air-port and a port opening into said vacuum-chamber, valve mechanism for controlling said ports, means for maintaining said valve mechanism in such condition as to normally close the vacuumport and open the air-port, means for shifting said valve mechanism so as to open the vacuum-port and close the air-port, and a passage extending from the supplemental pneumatic to the vacuum-chamber, said passage being constantly open, substantially as set forth. I

8.v Apneumatic-act-ion, comprising a structure consisting of a pair of side walls, flexible material extending between said Walls, a member arranged between the walls andattached to the flexible material so as to divide the space between the Walls into two chambers, the said member and the side Walls being'relatively movable, means whereby the atmospheric air normally communicates with the interior of one of such chambers, mechanism by which the air can be withdrawn from such chamber as desired, and means for constantly maintaining a vacuous condition in the other one of said chambers, substantially as set forth.

In witness whereof I hereunto subscribe my name this 7th day of August, A. D. 1900.

CHARLES 'L. DAVIS. 

